Automatic control for pressure apparatus.



irnNnr I?.v 'rn-OMA. o-r-senn courier, nonnina,

ATENCr OFFICE.

.AUTOMATIC CONTROL FG PRESSURE APPBATUS.

Specification f Illetters latent.

Application filed December 21, 1909.- Seral No. 534,381.

State of Montana, have invented new and useful Improvements in Automatlc 0011-'V trol for Pressure A paratus, of whlch the following is a speci cat-ion. v The invention relates to an automatlc control for pressure re,'gu lators.in use on air compressors, being more particularly (llrected to a means in the nature of a safety device whereby the engine is automatically throttled when the working air pressure drops to a. point of danger from any cause whatever. l

The main object of the present mvent1on is the provision of an automatic control for the admission of steam to the pressure regulator which control `is 4governed entirely bythe line air ,pressure,-the construction providingjor the admission of steam to the regulator and-a' consequent throttling of the engine upon the diminution of air pressure beyond a predetermined point, whereby to prevent danger incident to the overwinning of ,the engine on the sudden decrease of its ordinary load. n

The invention in its preferred details of construction will be described in the following specification, reference being had particularly to the accompanying dra-wings, 1n whieh:-

Figure 1 is a view in elevation illustrating the improvement. Fig. 2 is a sectional view of the automatic governor, the parte being shown in elevation. Fig. 3 1s an edge elevation of a slightly modified form. Fig. 4 is a front elevation of the same.

Referring particularly to Figs. 1 and 2, wherein is shown the preferred form of details, the impro-ved automatic control includes a pipe section 1 having communication with the air line at 2 and with the ordinary pressure regula-tor ln the pipe section [between the air inlet- 2 and. the pressure regulator is an ordinary pop valve 4 and also a wing valve 5, the latter permitting the free passa e of air through the pi e to the regulator w ile preventing travel o the fluid in the opposite direction. The air-lineconncctor 2 is also in open conununication with an additional ipe section 6, and in the latter is arranger the improved governor shown more particularly in' F ig. 2.-

As shown the governor comprises a casing 7 in which is arranged a partition 8 Patented-July 5,1910 i centrally formed to provide a valve seat 9 on its lower surface. A conical valve 10 is arranged to coperate with the seat 9, said valve being provided with a. depending stem 11 guided in a sleeve 12 projecting up wardly from the bottom of the casing and an upwardly extending stem 13 which will herelnafter be termed the stop rod. The stop rod extends to and through the top of the casing, and the weight of the valve. and stems 1s nearly but not quite equated by the spring 14 coiled about the depending stem about the valve proper and the stem-- l1. The casing 7 is provided with an inlet 15 1n Open communication with the pipe section 6, said inlet opening into the casing below the partition 8. An outlet section 16 is provided on the casing which is formedat a point intermediate its ends with an interior, transverse partition 17 and immei dlately adJacent said partition with an opening 18 forming a valve seat. A sleeve-like extension 19 surrounds the valve seat-.and vis adapted to receive at its upper end a cap' member 20 formi-ng a housing for the valve stem 21 carrying at its lower end a vulve 22 for coperation with the seat 18. Beyond, the opening 1S and within the sleeve extension 19 the outlet section 16 is formed with an opening 23 establishing communication between the outlet section beyond the partition 17 and the sleeve 19. By this construction the air pressure can reach the relatively outer portion of the outlet section 160111 by passage through the opening 18, whici opening 1s controlled by the valve 22. A. piston 24 is mounted in the outlet section 16 beyond the opening E23, and provided with a Stem 25 which projects through the cap 26 closing the end of the outlet section.

The piston 24 is to be directly affected by the air pressure passing the valve 22. A. coil sprlng 27 encircles the valve rod 21, being tensioned to a particular degree, as will presently appear. is extended to provide a supporting -lip 28 immediately underlying the projecting end of the. pistou stem 25.

The casing 7 is preferablr closed at the The outlet section respective ends b v removable caps, the upper cap is provided at one end with au extension 29 in which is pivotally mounted one end of a lever 3()7 a guide-projection 3l extendin from thc cap to guide .the lever in vertida plane. The opposing-end of the levc1-80 is,

through the medium of a link 3Q, connected lo an irai It; controlling a valve 34 arranged in a pipe 255 open to the steam' supply alud beyond thc valve 3l comniuiiicating with the pipe section 1 ndgaceiit the pressure regulator 2l. A. weight 25u is ad]ustably mounted on the lever 30 and normally operative to depress the link connected end of the said lever with the e..'ect to open the valve 34 and admit. steam to the pressure regulator. The spring 27 on' the valve rod 2l, hereinbefore referred to, is tensioned so as to require a slightly greater pressure to operate the valve 22 than would be necessary to support the weight 3G. A trip rod 3i' is pivotally connected to the lever 30 and so positioned that its free lower end may rest upon the lip 28 of the outlet section of the governor. The pivotal connection of the trip rod 3i' is slightly in advance of the position of the lip 28 toward the link connected end of the lever, so that when the trip rod is forced oli the lip it will be held by gravity in such position that its lower end will be beyond the lip, as will be obvious from Fig. 2- The trip rod 37 is of such length that when supported on the lip 28 1t will sustain the lever so as to hold the valve 34 closed and in such position that the lever will be slightly higher than the extreme upper position of the stop rod 13.

In operation the device is manually set by placing the freeend of the rod 37 on'the lip :28 thereby raising the lever 30 against the influence of the weight. and closing the valve 34:. Then the air has reached a pre determined pressure the valve 10 is of course closed and the valve 22 opened to permit the air pressure to act upon the piston 24 and, thi-ou h the medium of the stem Q5, force the trip rod oill the lip 28, rl"his permits a slight downward movement of the lever until it engages and is supported by the uper end of the stop rod, which of course has een moved upwardly by the air pressure on the valve 10. The lever is still supported in the position to maintain the valve 34 closed, that is so that the usual opcratlou ensues until upon any sudden reduction in the air pressure the pressure on the valve 10 is released and the stop rod permitted to move downwardly under the influence of the weight on the lever. The Valve 3l is thus opened, steam is admitted to the res sure regulator and operates ou the piston therein to throttle the engine and prevent an excessive and dangerous speed thereof.

ln Figs. 3 and 4 l have shown a sligifhtli1 dill'erent form of engine control in which the throttle rod. 38 is provided with a drinn 39 on which is wound a cable 40 extending beyond the drum and over the. elevated pulley 41 and terminally provided with a weight 42. A ratchet wheel 43 is secured on the drum, the teeth of which are dcsigned to he normally engaged by a dog 44 carried on a rod 45 mounted in a guide 46 secured on an extension 47 from the engine structure. The rod l5 is connected to a lever 48 pivotally mounted ou the extension 4:7 and said lever is iii turn connected to the weight lever 30 of the rovernor construe` tion by the link 32. In t is form of device ie operation et' the lever 30 on a decrease of air pressure will withdraw the dog 44 from the ratchet and permit the weight 42 to operate the drum and thereby throttle the steam.

In connection with the above apparatus it is to be articularly noted that the device is manual y set and that the air pressure does not gain control thereof until such pressure has reached a redetermined point. This is an important attire as hy a mere regulation of the tension of the spring 27, which may be accomplished by adjusting the cap 20 longitudinally in the sleeve 19, as illustrated in Fig. 2, and the consequent adjustment of the weight 36 on the lever, the controlling pressure at which the device may be set for automatic operation may be readily regulated.

Having thus dcrbed the invention, what is claimed as new, is

1.- An air pressure apparatus including a motor thrott-ling means comprising a gravity operated lever, manually operable means for initially holding said lever against op eration, means actuated by the predetermined air pressure to relieve the lever of the holding means, and means automatically actuated by said predetermined pressure to hold the lever against throttling movement.

2. An air pressure apparatus including a motor tlirottling lever, a trip lever arranged for manual operation to normally hold said lever a einst throttling movement, means act-nate by a predetermined air pressure to operate the trip lever to relieve the throt tlin lever, and a stop rod operated by said pre eterinined pressure to prevent throttling movement of said lever.

3. An air pressure apparatus including a gravity operated throttling lever, a valve easing open to the air pressure, a valve in said casing designed to be effected by the air pressure. a stop rod carried by the valve and adapted to be projected in the path of movement of the tlirottling lever, an outlet passage iu cominiinicat-ion with the casing, a valve coi'itrolling said aussage, a piston arranged in the passage eyelid the valve, a. stein carried bythe piston, a trip lever couneeted to the tliiottling lever, and a lip carried by the casing to support. the free end of the trip lever in the path of the piston stem` said trip lever when sup oited ou the lip holding the tlirottling ereiagainst. throttling movement.

4. An air pressure apparatus including a gravity operated thyottling lever, g, valve casing open to the zur pressure, a trip lever connected to the throttling lever, a projeetion carried by the valve casing to receive and support the trip lever to hold the throttling lever against throttling movement, and means arranged in seid casing to be operated by u predetermined air pressure to simultaneously force the trip lever from the 10 projection and move into the path of the throttling lever, a supporting element, whereby to relieve the throttling lever of the fixed support und subject it to n support by the air pressure.

In testimon whereof I affix my signature 15 in presence o two witnesses.

HENRY F. THOMA. Witnesses:

JOHN N. Pence, J AMES A. VERNON. 

